Erosion at the bottom of the Straits of Mackinac has opened up an 81-foot stretch of Enbridge’s Line 5 petroleum pipeline that is unsupported by lakebed or steel supports.

That is 16 feet longer than the minimum amount of unsupported line that is allowable under the 1953 easement, which originally granted Enbridge the right to lay down its pipeline in the Straits.

Technically speaking, Enbridge is not in violation of the law yet, but the company could be if the problem goes unresolved for too long. And part of that is out of Enbridge officials’ hands while they wait on the proper permits to correct the issue.

Enbridge announced the issue in a press release late Wednesday afternoon.

Earlier that same afternoon, officials from the company were with Northern Michigan reporters — including a Petoskey News-Review reporter — on a two-and-a-half hour press tour around the Highland Eagle, a ship which is doing tunnel research work for the company in the Straits of Mackinac. At no point during the presentation did any Enbridge official mention the span issue, despite the fact that they had been tracking the problem for about a month, and preparing to go public with news that day.

The Petoskey News-Review is a sister publication to the Herald Times.

That evening, during an open house in Petoskey, Enbridge spokesman Ryan Duffy explained to the News-Review that the company wanted to inform the state of the issue first, before commenting publicly.

By design, Line 5 is supported by the lakebed of the Straits of Mackinac. However, over time, parts of that lakebed can wash away, leaving unsupported spans. If those spans grow past the 75-foot limit, Enbridge is required to correct the issue, which is accomplished by installing steel “anchor supports” to those exposed areas.

“The Straits of Mackinac is a dynamic and ever-changing system, because of the flows, and so you see scouring of the lakebed, which changes the bottom, essentially,” Jennifer McKay, policy director of Tip of the Mitt Watershed Council, said. “So, at one time what was supported, can wash away.”

Duffy noted that sometimes such changing sediment patterns can cause the spans to shrink instead of grow, but that is not the norm.

Enbridge is required to conduct routine inspections of the pipeline to insure it stays in compliance. Officials maintain that the current span does not constitute a safety issue.

“It’s not a safety concern, because we’ve had engineers look at it, and they’ve said you could have twice as big a span and it wouldn’t necessarily be a safety issue, but we’ve always abided by the easement — 75 feet — if it gets close to that, we flag it,” Duffy said.

Past reports by the Gaylord Herald Times, sister paper to the News-Review, have shown that Enbridge has violated the anchor span rule multiple times over the decades.

“That’s one of the concerns that a lot of the organizations have, is that the lakebed is consistently changing because of that dynamic flow that we see in the Straits of Mackinac,” McKay said. “It’s just such a complex ecosystem, particularly right there.”

Prior to this week’s announcement, Enbridge was already in the process of adding more anchor supports to the line as an extra precaution. They are still waiting on a permit from the U.S. Army Corps of Engineers, which they applied for in March 2018, to install more anchors.

“We have a crew in the Straits, they have steel anchor supports, they’re ready to go, they could do it in two days, but we just need that permit,” Duffy said.

Technically, the company has 90 days to correct the issue after the Michigan Department of Natural Resources issues a warning that they are in violation. But that timeline is a bit of a moving target because the state has not issued such a warning as of press time. The agreement signed between Enbridge and the state in 2018 also states that if the company finds a 75-foot span, it must report it to the state within 30 days.

Duffy said that the company noticed the span was growing about a month ago, but was waiting to see if the Army Corps permits would be granted in time. By Wednesday, Enbridge determined that it had to report the matter to the state.

Lynn Rose, a spokesperson for the Army Corps of Engineers, says the permit is a “high priority” item for the agency, and officials there are working on a decision soon. She noted the agency did have a final set of questions for Enbridge to answer before making a decision, but those requirements were fulfilled July 23.

Duffy suggested that the currently proposed plan to place the Straits pipeline segment in a tunnel would help solve such problems going forward.

“The tunnel project ... is a good solution going forward, because we wouldn’t have to worry about supports, we would have to worry about span issues if it was in a tunnel under the lakebed,” he said. “That’s our opinion.”